Finding the Fourth Proportional to 12,935.56, 19,400.46 and 5,142.28

Step by Step Solution

1. Step 1: Write the proportion equation
   12,935.56 : 19,400.46 = 5,142.28 : x
2. Step 2: Convert to fraction form
   12,935.56/19,400.46 = 5,142.28/x
3. Step 3: Cross multiply
   12,935.56x = 19,400.46 × 5,142.28
4. Step 4: Simplify right side
   12,935.56x = 99,762,597.45
5. Step 5: Solve for x
   x = 99,762,597.45/12,935.56
6. Step 6: Final answer
   x = 7,712.28